Belt conveyer for loose aggregates



sept; 7, 1954 Filed June 18, 1951 l H. w. HURD ETAL BELT coNvEzER FOR LOOSE AGGREGATES 9 Sheets-Sheet l Sept. 7, 1954l H. w. HURD ETAI. 2,688,394

BELT CONVEYER FOR LOOSE AGGREGATES Filed June 18, 1951 9 Sheets-Sme?l 2 INVENTORS Harg/ IM Hurd Francis H. J'ams BY d Maa/f Sept 7, 1954 H. w. HURD ETAL 2,688,394

BELT CONVEYER FOR LOOSE AGGREGATES Filed June 18. 1951 Y 9 Sheets-Sheet 3 l 0 INVENTORS Hargg W /urd -F/jcmcis H. James l BY f7/MMM H. W. HURD ET AL BELT CONVEYER FOR LOOSE AGGREGATES sept. 7, 1954 9 Sheets-Sheet 4 .Filed Ju'ne 18, 1951 a; la@ a INVENTORS Hargy Ml Hurd Y Francis H. James Sept. 7, 1954 H. w. HURD ETAI.

BELT coNvEYER FOR LoosE AGGREGATES 9 Sheets-Sheet 5 Filed June l, 1951 INVENTORS Hag/ W. Hurd BY Francis H. James ,ify

Sept. 7, 1954 H. w. HURD ErAL BELT coNvEYER PoR LoosE AGGREGATES `sa sheets-sheet e Filed June 1s. 1951 154 9% y@ Se 3% 11W/mfom Harig W Hurd Fran'cl's H. J2e/nes SePtf 7, 1954 H. w. HURD ET AL 2,688,394

BELT CONVEYER FOR LOOSE AGGREGATES n INVENTORS Harr W. Hurd Sept. 7, 1954 H. w. HURD ET Al. 2,688,394v

BELT CONVEYER FOR LOOSE AGGREGATES Filed June 18, 1951 9 Sheets-Sheetl 8 INVENTORS W. Hurd H. J'am es HarLq BY Francis Patented Sept. 7, 1954 BELT CONVEYER FOR LOOSE ALGGREGATES Harry W. Hurd and Francis H. James, Boise, Idaho, assignors toHurd and James, Inc., Boise,

Idaho ApplicationJune 18, 1951, Serial No. 232,104

s claims.l 1

The present invention relates' to improvements in a belt conveyor for loose' aggregates' they' may be operated at different angles to the horizontal as the occasion requires. These conveyors are most generally operated in` areas exposed to the atmosphere with' no cover or protec tion of any sort. of weather conditions and the material which they must move is of such nature as to create dust and falling particles;

The primary object of the present invention is to provide in a single frame of sheet metal a supporting beam for the belt andl load whichV mounts troughing rollers forl the upper flight of` the belt and which enclosesv and carries the lower flight of the belt, protecting it from fallingA loose material. andv the elements. The belts commonly used forconveying' loose materials are largely constructed of rubber and like material which deteriorates' more. rapidly when exposed to direct sun and' out door variations-in weather. With the present invention this exposure is cut in half by the same beam construction that sup'- ports the load. The same beam construction also keeps loose and falling materials Vaway from' the inner face of the belt and'keeps loosematerial from piling up on the beam to` add further weight to the construction.`

A further object of the inventionis to provide a single frame support for the` belt' in combination with troughing rollers to maintain the belt trough-shaped in cross sectionfso that accumulations of solids on the conveyor are substantially' avoided and increased air circulation is provided transversely of the belt and frame to keep the temperature down and to reduce resistance to cross winds.

Another detailed object of this invention is the provision of a frame and roller construction assembly having novel means by'which a plurality of duplicate sections or lengths' may' be joined' together to provide the desired over.` all length of conveyor.

They are subjected to all sorts 1t is also an object of the invention to' provide a supporting frame with novel head end and' tail end assemblies of such nature as topermitmounting and removing of an endless belt on the assembled conveyor frame without cutting the belt and without disconnecting the frame. The inventionl contemplates the provision in the assembled conveyor of a novelY supporting' means for the end'. pulleys of.` the" belt so that av Wide latitude in length'Y adjustment is permissible; Tl-ie head and tail end assemblies are of` such': a nature'fthat` it is a simple matter to supply ther motive' power! t'oeither end.

It isal'so` a purpose of this invention to provide means whereby th'e belt is vt'ro'ug-l'iedboth on itsl'oad carrying flight andv on itsv return flight, the troughing on the returnl flightbeing a reversal of the bending of the belt in order to train the return night soas to prevent movement sidewise and at the same time to give the belt `opportunity to` correct itself from the troughing" stresses on the loaded flight,

Another and more detailed object of this' nvention is to provide means fortroughin'g the upper night of the conveyor'belt 'which means' o'perates to vibrate the belt in such' a fashion as to bring the material toward the center of the belt and for certain' types' of material',v to keepv the material' bouncing on the belt at' all times. The troughing construction is shown and described hereinafter with several' modifications in details, the objects of these modied details being to improve the. operation under certain conditionsas will be more f-ully explained in the detailed description.

Other objects and advantages of the invention. will appear from the following detaileddescription and the accompanying drawings wherein a preferred embodiment of the invention is shown. 1t should be understood however, that the drawings and descriptionl are illustrative only and are not intended to lim-it the invention except insoiar asit islimited by the claims.

I-n the drawings:

Figure 1 isy a somewhat diagrammatic plan view of av conveyor for" loose' aggregatesv embodying our invention;`

Figure 2 is alongitudinal sectional viewtaken on' the line 2-2 of ligurek 1;

Figure 3 is an enlarged sectional view taken on the line 3-3- of Figurel;

Figure i is an enlarged sectionalview taken onthe same line as Figure but showingthe junction. between two 'sections` of the conveyor, the` 3 upper flight of the belt being left oif for the sake of clearness.

Figure 5 is a sectional view taken on the line 5 5 of Figure 3;

Figure 6 is a sectional view taken on the line 6 6 of Figure 4;

Figure 7 is an enlarged view in side elevation of one end of the conveyor, the view being taken substantially on the line 'I 'I of Figure 1;

Figure 8 is an enlarged view in side elevtaion of the other end of the conveyor, the View being taken substantially on the line 8 8 of Figure 1;

Figure 9 is an enlarged fragmentary sectional View taken on the line 9 9 of Figure 8;

Figure 10 is a section view taken on the line I I0 of Figure 7;

. Figure 11 is a sectional view taken on the line II II of Figure 8;

Figure 12 is an enlarged fragmentary sectional view taken on the line I2 I2 of Figure 7;

Figure 13 is a plan view with certain roller units removed of a troughing roller assembly used in the conveyor;

Figure 14 is a side view, partly in section, of the troughing roller assembly shown in Figure 13;

Figure 15 is an enlarged sectional View taken on the line I I5 of Figure 13;

Figure 16 is a View similar to Figure 14, showing the troughing roller assembly modied to produce vibration of the belt;

Figure 17 is an enlarged fragmentary section view taken through one of the troughing roller umts shown in Figure 16, on a vertical line, the belt being shown in this gure in full lines and dotted lines with the sectioning being left out so that the different positions of the belt may be seen;

Figure 18 is a sectional view taken on the line I8 I8 of Figure 17;

Figure 19 is a plan view of a modiiied form of the troughing roller assembly which provides for adjustment of the troughing of the belt;

Figure 20 is a view in side elevation of the assembly shown in Figure 19;

Figure 21 is a sectional view on the line 2I 2I of Figure 20;

Figure 22 is a sectional view similar to Figure 5 showing a modified construction of the frame; and

Figure 23 is an enlarged fragmentary sectional taken on the line 23 23 of Figure 22.

Referring now in detail to the drawings, the invention is embodied in a belt conveyor that is particularly adapted for use in handling loose material such as sand, gravel, coal, ore, clinkers, grain, concrete and commodities that ilow or may lfall over the side edges of the loaded belts.

When the loose material falls over the side of the troughed belts, it may do serious damage to the belt if it finds its way to the return or lower :Hight of the belt. Any exterior framework or parts that will catch dust or loose material serve to multiply the difficulties of protecting the belt. In long flights of conveyors the problem of cross winds defiecting the unloaded lower flight of the belt must also be considered. The conveyor constructed in accordance with our invention embodies a sheet metal frame I which is also constructed as to be completely self supporting and capable of supporting the loaded belt with the pulleys and troughing rollers that are necessary for the belt operation. This supporting frame I is combined with a head frame unit 2 and a tail frame unit 3 which mounts two pulleys 4 and 5 for an endless belt 6. Troughing roller assemblies 'I are mounted on the frame I to support the upper flight of the belt 6 which carries the load. The lower ight of the belt 6 is carried by roller assemblies 8. As shown in Figures 1 and 2 only the end portions of the frame I are included with the head and tail units 2 and 3. It will be appreciated that the length of the frame I will vary depending upon the desired length of conveyor needed and as many of the roller assemblies I and 8 will be used as are necessary to support the belt 6 throughout the length of the conveyor.

Referring now to Figures 3 to 6 inclusive the detailed construction of the frame I will be described. In its preferred form this frame comprises two main sheet metal strips I0 and II of suitable thickness and length. These strips are bent along the line parallel to one edge as indicated at I2 and I3. The angular bend at I2 and I3 is about 105 to 120 degrees. The two anges I4 and I5 formed by this bend are placed against each other as shown clearly in Figures 5 and 6 and are welded together to form a longitudinal rib. The top portions I6 and I'l of the metal strips IIJ and I I will slope downwardly and outwardly from the rib formed by the flanges I4 and I5. The strips are bent again at I8 and I9 to form side portions 20 and 2| which extend downwardly substantially parallel to each other. Along the lower edges of the side portions 20 and 2l the strips are bent inwardly to provide horizontal flanges 22 and 23. Thus the two main strips I 0 and II, when bent as indicated, provide an inverted trough shaped beam or frame which has a stiffening rib centrally thereof extending downwardly from the topmost part of the frame. The top portions I6 and I'I form a roof that slopes about 15 to 30 degrees to the horizontal from the center of the frame to the outer side edges.

The frame I is completed by providing diagonally extending strips 24 and 25 that extend upwardly and outwardly from the center edges of the flanges 22 and 23 to join the side wall portions 20 and 2I. The strips 24 and 25 have their edges afxed to the main strips in any suitable manner such as by welding. A truss plate 26 extends in zig zag fashion lengthwise of the frame I between the side portions 20 and 2| above the upper edges of the strips 24 and 25. The truss plate 26 is aiiixed to the side portions 20 and 2I by welding. It will be noted that the uppermost portions of the truss plate 26 overlap with the central rib formed by the flanges I4 and I5. The truss plate 26 is notched to receive the rib and the rib and truss plate are welded together where they meet.

The troughing roller assemblies 'I are mounted on the top portions I6 and I1. The roller assemblies 6 have mounting portions 27 and 28 which are mounted to the flanges 22 and 23 by bolts 29 and 30. The upper flight of the belt 6 is thus supported above the V-shaped portions of the frame I so that any material falling from the top flight of the belt will strike the sloping portions I6 and II and fall oif the sides of the frame, Likewise an air passage crosswise of the conveyor is provided between the belt 6 and the frame I. This air passage is narrowest directly over the center of the frame and expands outwardly to the outer edges of the belt. Air can ow readily between the belt and the frame and this keeps down the accumulation of dust. It also reduces resistance to cross Winds.

Ihe lower roller' assembly 8 holds the lo-wer flight ofthe belt 6 well above the flanges 22 and 23 so that the entire lower flight of the belt 6 is enclosed on the top and sides. It will be appreciated that there is practically no opportunity for loose material to get on top of the lower flight of the belt 6. Furthermore the lower night of the belt is protected from sun, rain and snow, which means that in the ordinary use of the device there is about one-half of the belt always protected. This is particularly advantageous in prolonging the life of the belt made of rubber materials which age much more rapidly in bright sunlight than they do when protected.

The frame preferably is made up in unit length sections that are joined together to provide a belt supporting frame of the desired length. It is preferred to provide the sections in eight foot lengths with means to join the several sections so that they may be used as a single beam of the desired length. The means for joining thesections is illustrated best by Figures 4 and 6. Each section is closed at both ends above the strips v24 and 25 by end plates 3| and 32. These plates are slightly larger than the outline of the side portions 28 and 2| and the top portions I 6 and i1, in order that they may be welded rmly to the ends of these portions.- Gusset plates 33 and 34 are welded to the end plates 3| and 32 and to the corresponding side portions and top portions of the frame sections. The end plates 3| and 32 are all drilled with matched holes so that they may be fastened together as indicated by bolts 35 and nuts 35. When the sections are connected together by the bolts 35, the bolts are under :tensional strains rather than shear. The plates `3| and 32 must of course be made sufficiently thick l to carry-the load.

As afurther means of strengthening the frame where two sections are joined together and at the .same time providing support for the lower flight of the belt 8, the roller assemblies 8 have their securing iianges 21 and 28 positioned at the junction of two sections and bolted to both sections by the bolts 29 and 30. The strips 24 and 25 have apertures 24a and 25a therein to provide access to the bolts. i

The head and tail assemblies 2 and 3 are illustrated best by Figures l, 2 and 7-12 inclusive. It will be appreciated that either of the pulleys 4 and v5 may serve to drive the belt. The pulley 4 is mounted between two side frames 31 and 38 by a shaft ,38. The side frames 31 and 38 are connected by a cross web 48 (see Figure 1), which may also be utilized vto secure the assembly 2 to the frame by bolting the end plate 32 of the frame to the web 48 by bolts 4I. The side plates 31 and 38 are further connected together by angle iron members 42 and 43 which may be removed to mount the belt `t. As shown, the side frame members 31 and 38 have outwardly turned anges 31a and 38a to which the members 42 and43 are bolted by bolts 44. The member Y42 has a plurality of attaching members 45 thereon that aroused for suspending'one end of the conveyor wherever necessary. The mounting of the shaft 39 in the side frames 31 and 38 is illustrated best in Figures 7, and 12. The pulley 4 is secured on the shaft in any suitable manner such as by collars 45 and 41 whichare flanged and bolted to the ends of the pulley 4 by bolts 48. The shaft 39 extends through elongated slots 45 and 55 which are provided in the side frames 31 and 38. Onthe outside of theside frames -31 and 3.8 spaced vertically extending angleirons5| and 52 are provided. The angle irons 5| are located at the outer end of the side frames 31 and 38 While the angle irons 52 are intermediate the ends of the side frames. Intermediate the angle irons 5| and 52, bearing block guides 53 and 54 are secured to each of the side frames 31 and 38. Slidable in the guides 53 and 54 is a U-shaped member 55 which is apertured to receive the shaft 39. Ak standard ball bearing unit 55 is bolted to the U-shaped member 55 and rotatably mounts the shaft 38. In order to adjust the shaft 38 endwise with respect to each side frame 31 and 38, we utilize the mechanism shown most clearly in Figures 7 and l2. This mechanism comprises two threaded blocks 51 and 58 vwhich are welded to the angle irons 5l and 52 and threaded bolts `58 and 68 that are threaded through the blocks 51 and v58. The heads 59a and 68a of the bolts bear against the ends of the U-shaped member 55. By rotating the bolts 58 and 58, they may be moved endwise with respect to the blocks 51 and 58. In this way the shaft 38 can be moved endwise in the side frames 31 and 38 properly to align the Vpulleyll and to take up slack in a drive chain or other connection made to a drive sprocket 8| that is shown in Figure l0 on the shaft 39. Lock nuts 52 and 33 are provided for the bolts 59 and 6D.

The tail `frame support 3 for the pulley 5 is illustrated in detail in Figures 8, 9 and 11. These iigures also illustrate the way in which the `pulley 5 is mounted on its drive shaft S5. The assembly 3 is composed of two side plates 68 and 61 which are flanged at the top and bottom with outwardly extending flanges indicated at 55a and 6822, and 51a and 81h. The side plates 66 and 51 are connected together at the top by a channel iron 58 which is welded to the side plates. A cross web 63 is also welded to the side plates 68 and 61 to further'connect the plates and to serve as a means for securing the end plate 3| of the frame I to the side plates. A removable channel 10 is bolted to the flanges 66h and 61h by bolts 1I to connect the side plates together at the bottom. The channel 18 must be removable for replacement of the belt 5.

The yshaft 65 is mounted to the side frames 56 and 61 so as to have a long adjustment lengthwise of the conveyor as will be presently described. The pulley 5 is rotatably mounted on the shaft by antifriction bearings 12 which have flanges 12a that are bolted to the ends of the .pulley 5. It is sometimes desirable that the drive of the belt be from the end portion 3 and the pulley 5 rather than from the pulley 4. As ameans of driving the pulley 5, we provide a sprocket wheel 1.3 on one end of the pulley .5, using a spacing ring 14 that is suitably secured tothe end of the pulley 5 and to the end of the sprocket wheel13.

The ends of the shaft 65 are apertured to receive screw threaded adjusting members 15 and v16. These adjusting members have nuts 11 and 18 on opposite sides of the shaft and the ends of the members 15 and 16 are secured to angle irons 19 and 88 that are secured to each of the side plates `58 and 51. The side plates 65 and 61 have elongated slots 8| and 82 therein through which the shaft 55 may pass. Angle irons 83 and 84 are provided on each of the side plates below and above the slots 8| and 82 and welded in place. These angle irons form a support for blocks 85 and 8 5 made of metal or of hard Wood and which carry the shaft 65. `The endsoffthe members 15 and 13 are locked in 7.. place in the flanges of the angle irons 19 and 80 by nuts 81 and 88. The angle irons 80 are removably bolted to the side frames to permit insertion of the shaft 05.

Whenever it is necessary to place a new belt 6 on the conveyor, it is possible with the construction hereinbefore described to remove the old belt and apply a new belt without either cuttingthe belt or dismantling the conveyor. The roller assemblies 8 have to be removed and the angle irons 42 and 43 and the channel iron 10 have to be removed. The pulley 5 is then moved by adjustment of the shaft 85 to its extreme left hand position as shown in Figure 2 and the amount of slack thus gained in the belt 6 permits the belt to be passed over one of the side frames 31 and 38. In this way a belt can be put on and removed from the conveyor with very little difficulty.

Referring now to Figures 13, 14 and 15, these figures illustrate the preferred form f the troughing roller assembly 1. The assembly comprises two side plates 90 and 9| which are anged at their lower edges as indicated at 90a and 9|a. The side plates are connected together at their ends by uprights 92 and 93 that have feet 94 and 95 which are bolted to the top of the frame I. Braces 96 and 91 are employed to give rigidity to the uprights 92 and 93 and to strengthen the roller assembly. The side plates S0 and 9| are connected by a plurality of roller unit supporting across ties 98. T'nese cross ties are all alike, each tie has a recess 99 extending downwardly from the top edge thereof and is slotted at |00 alongside the recess 9. Three roller assemblies I0 I |02, and |03 are utilized to form a support for the belt 6 which will hold it in a trough shape. The roller assemblies may be constructed in various fashions. However, as shown, each one comprises a shaft |04 on the ends of which are provided two ball or roller bearing units |05 and |08. These units are grooved at the sides as indicated at |01 and |08 so that the grooves will receive the side edges of the recesses 99 provided in the cross members 98. The bearings |05 and |06 thus position a roller unit between two of the cross members 98 and rotatably mount the roller unit. The bearings are xed in place by bending over the portion |00a of the cross plate 98 between the slot |00 and the recess 99. This construction is illustrated in detail in Figure of the drawings.

Each of the roller assemblies |0I, |02 and |03 is preferably made up in detail as illustrated in Figures 17 and 18 of the drawings. These figures in combination with Figure 16 illustrate the way in which the rollers may be made to vibrate the belt 8. However, the roller assembly is the same in Figures 13, 14, and 15 as it is in Figures 16, 17 and 18 except for the vibration feature. Each roller unit is preferably made up of the shaft |04, a i'lxed plate |09 that is welded to the shaft |04, a plurality of belt receiving disks ||0, spacer disks I|| and end plate ||2, clamping bolts H9, passing through the plates |09 and I2 and the several disks I0 and and nuts I |4 for the bolts ||3, Preferably the belt receiving disks ||0 are constructed of rubber or a rubber belting sheet material made either of synthetic rubber or natural rubber composition. The spacer disks |I| are brous such as the hard tempered fiber boards sold under the trade name Masonite The bolts ||3 are set 120 degrees apart about the shaft |04 and are spaced outwardly from the shaft so that they pass through the spacer disks I|| as well as through the disks I I0. The spacers need not extend inward all'the way to the shaft |04 so they have larger apertures cut in them. It is best however, to have the disks I0 apertured with an opening just the right size to receive the shaft |04. The number of disks I I0, used as a unit, may vary to suit the particular type of load to which they are subjected. This pulley assembly has been found to be particularly advantageous in prolonging the life of the load carrying belts under hard usage. They are yielding to the belts and produce a minimum of slippage to wear the belts.

For certain purposes it is desirable to give the belt more motion than it normally will have in traveling over the rollers. With the improved roller assembly shown in Figures 16 to 18 inclusive, it is contemplated that the belt can be vibrated vertically as it passes over the rollers. The advantages are several. The vibration will tend to move the load inwardly over the central portion of the belt if the outer edges of the belt are vibrating. If the vibration is continued all the way across the belt, the load can be bounced on the belt so as to prevent sticking, or burning of the belt, when relatively hot material such as ashes and clinkers is being conveyed. The way in which the roller assemblies are made to vibrate the belt is by offsetting the disks I0 eccentrically with respect to the shaft |04. This is illustrated clearly by Figures 17 and 18 where the left hand disk |I0 is offset horizontally with respect to the shaft |04 a certain amount. The next disk to the right is offset diagonally upward at an angle of 45 degrees from the shaft the same amount. The next disk ||0 to the right is offset vertically with respect to the shaft a like amount. The next disk ||0 to the right is offset upwardly at an angle of 45 degrees a like amount, but the offset in this disk is at a right angle to the offset of the second disk from the left hand end of the assembly. With the offset disks staggered this way around the shaft |04, the outline of the disks when viewed in section on the line I8--I8 of Figure 17 appears as viewed in Figure 18. Figure 17 illustrates in full lines and dotted lines the changing position of the belt 6 as the shaft |04 is rotated through an angle of 90 degrees. It is evident that with this sort of arrangement the belt can be vibrated as much as desired, the rise and fall of the belt being measured by the eccentricity of the disks. Of course it is not necessary that all of the disks be offset with respect to each other. A series of disks may have the same offset.

Figures '19, 20 and 21 illustrate a different form of troughing rollers that may be used where it is necessary or desirable to vary the angularity of the trough with respect to the horizontal. In this construction the troughing roller assembly is made up of two side plates ||5 and ||6 flanged outwardly at the bottom edges and connected together by angle irons |1 and ||8 at the ends. A central web ||9 connects the side plates ||5 and I I6. A roller assembly unit is made up of two side pieces |20 and |2| and cross pieces |22 and |23, all welded integrally together. A series of rollers |24 is fixed on a shaft |25 which is journalled by bearings |26 and |21 in the cross plates |22 and |23. This assembly just described is secured between the plates ||5 and ||6 by bolts |28 and |29 that are passed through round apertures at one end of the assembly and extend through elongated apertures |30 in the plates ||5 and IIB. A plurality of apertures |3| are provided near the outer ends of the plates ||5 and H and bolts |32 and |33 secure the plates |25-|2| to the outer ends of the plates ||5 and H6. It is evident that by shifting the bolts |32 and |33 to different apertures |3l, the position and angularity of the roller assemblies can be changed to suit aparticular condition.

For supporting the lower night of the belt the roller units 8 are utilized preferably with outer rollers |65 of larger diameter than the intermediate rollers ISI on the supporting shaft |52. This imparts to the lower night of the belt a trough shape in cross section which is not so pronounced as the troughing imparted to the upper night of the belt. However, it is sufficient to serve to center the belt `on its return night and keep it from riding toward one side cr the other. The troughing action also serves to reverse the transverse bending of the belt from that which occurs in the upper night and in this respect helps to prevent the belt from taking a permanent set due tothe troughing. The shaft |53 is supported on bearing members |53 and |55 which are bolted to cross bars |55 and |55 of the assembly 5. The supporting frame of the assembly 8 comprises two plates Iii? and |55 which are flanged outward at their lower edges. These plates If' and |58 are connected together at the ends thereof by the members 2? and 28 which serve to mount the roller assembly 8 to the nanges 22 and 25 of the frame I.

Referring now to Figures 22 and 23, these ngures illustrate a further modification of the invention. The frame I' shown in cross section in Figure 22 comprises two sheet metal strips |35 and |35 which are alilre and which are bent at |55 and |57! to provide inverted V-shaped trusses. The short side portions |35 and |55 of the strips are secured together at lli-.) by welding. The main portions of the strips |55 and |35 extend outwardly and downwardly from the bends |35 and iti and then are bent inwardly to provide horisontal flanges |l| and |52. These flanges are reenforced by vertical strips |53 ,and Idli that are welded to the flanges and to the main side portions ,of the strip A, truss plate |55 .extends across the frame member at the top edges of the strips |1133 and Mii and is welded to the main strips to the lower ends of the portions |35 and |53. The convex cover strip Ille closes the space over the portions |58 and |59, being integrally joined to the vstrips |515 and |35 at the bends |515 and rThebelt 5 -is carricdon topof the frame I by a roller assembly |45, the details of which are illustrated more fully in Figure 23. A roller assembly 8 like that shown in the main form of the invention is secured to the flanges Mil and |42 by bolts |48 and |59. The strips |43 and IM are apertured as indicated at |l|3a and |450'. to permit access to the bolts.

The roller assembly |47 utilizes a single shaft |50 which is supported onan assembly frame I 5| by two bearings |52 and |53 of the anti-friction type. The construction is such that different size pulleys |54, |55 and |55 may be utilized to trough the belt E without requiring the belt to slip on any particular pulley. To accomplish this result without use of special bearings the pulley |55 is nxed to the shaft |55 by a key |51. Pulleys |54 and |55 are rotatably mounted on the shaft |55, using simple and inexpensive bearings and are held in place by any suitable means such as collars |58. Oil impregnated bearings |59 may be used quite economically in this construction. When the roller assembly is constructed as just described the intermediate pulley |55 when en- Cil gaged by the belt will rotate the shaft |55. ASince the larger pulley |54 has a greater circumference than the pulley |55, it will turn at a slightly slower rate and will therefore rotate on the shaft |50 in a backward direction. The pulley |56, being smaller than the pulley |55 will have to rotate on the shaft |55 in a forward direction, the rate of rotation however, willbe very slow so that the bearings willl have a longer life and will need little or no attention.

Having thus described our invention, we claim:

1. A belt conveyor adapted for transporting loose aggregates, va self supporting frame comprising a beam consisting of an inverted trough-like sheet metal member, the top wall of which slopes downwardly from the center toward both the side edges thereof, the member having in-turned flanges at its lower side edges assemblies of belt supporting rollers mounted on the top of said member in longitudinally spaced relation, operable to carry the upper loaded flight of an endless belt above and spaced from the member, assemblies of belt supporting rollers mounted on said flanges and extending across the member between the lower side edges of said member operable to support the lower return night of said endless belt within the trough-like member above the lower side edges thereof, a pair of side frames secured to each end of said trough-like member, a pulley mounted by each pair of side frames, Vand an endless belt extending around the pulleys and over the roller assemblies.

2. A belt conveyor adapted for transporting loose aggregates, a self supporting frame comprising a beam consisting of an inverted trough-like sheet metal member, the top wall of which slopes downwardly from the center toward both the side edges thereof, said member having a longitudinally extending rib therein integral with and depending from said top wall, the member having in-turned nanges at its lower side edges assemblies of supporting rollers mounted on the top of ,said member in longitudinally spaced relation, operable to carry the upper loaded night of an endless belt above and spaced from the member, assemblies of belt supporting rollers mounted on said flanges and extending across the member between the lower side edges of said member operable to support the lower return night of said endless belt within the trough-like member above the lower side edges thereof, a pair of side frames secured to .each .end of said trough-like member, a pulley mounted by each pair of side frames, and an endless belt extending around the pulleys and over the roller assemblies.

3. A belt conveyor adapted for transporting loose aggregates, a self supporting frame comprising a beam consisting of an inverted troughlike sheet metal member, the top wall of which slopes downwardly from the center toward both the side edges thereof, the member having inturned flanges at its lower side edges assemblies of belt supporting rollers mounted on the top of said member in longitudinally spaced relation, operable to carry the upper loaded night of an endless belt above and spaced from the member, assemblies of belt supporting rollers mounted on said flanges and extending across the member between the lower side edges of said member operable to support the lower return night of said endless belt within the trough-like member above the lower side edges thereof, a pair of side frames secured to each end of said trough-like member, a pulley mounted by each pair of side frames, and an endless belt extending around the pulleys and over the roller assemblies, one of said pulleys being movable in its side frames toward the other pulley a distance suicient to enable the belt to pass over the side frames carrying the other pulley.

4. In an endless belt conveyor, a belt and load carrying sheet metal frame comprising top wall portions sloping downwardly from the center to the outer side edges of the frame, side wall portions extending downward from the outer edges of said top wall portions, inwardly extending longitudinal flanges at the lower edges of said side wall portions, a longitudinal rib depending from the upper edges of said top wall portions, and a zigzag truss plate extending lengthwise of the frame, the side edges of the truss plate being affixed to the side wall portions.

5. In an endless belt conveyor, a belt and load carrying sheet metal frame comprising top wall portions sloping downwardly from the center to the outer side edges of the frame, side wall portions extending downward from the outer edges of said top wall portions, inwardly extending longitudinal flanges at the lower edges of said side wall portions, a longitudinal rib depending from the upper edges of said top wall portions, and a zigzag truss plate extending lengthwise of the frame, the side edges of the truss plate being afxed to the side wall portions, and the rib intersecting and being affixed to the truss plate at the upper bends thereof.

6. A belt conveyor adapted for transporting loose aggregates, a self supporting frame comprising a beam consisting of an inverted troughlike sheet metal member, the top wall of which slopes downwardly from the center toward both the side edges thereof, said member having inturned flanges along the lower side edges thereof, assemblies of belt supporting rollers mounted on the top of said member in longitudinally spaced relation, operable to carry the upper loaded flight of an endless belt above and spaced from the member, assemblies of belt supporting rollers mounted on said flanges between the lower side edges of said member with the belt supporting surfaces of the rollers spaced above the flanges whereby said rollers are operable to support the lower return night of said endless belt within the trough-like member above the flanges at the lower side edges thereof.

7. In a belt conveyor adapted for transporting loose aggregates, a self-supporting, belt supporting inverted trough-shaped frame member comprising a pair of main sheet metal strips each bent adjacent one side edge about degrees to 120 degrees forming top depending anges, said flanges being united into a central rib connecting said portions, the strips having top portions extending outwardly and downwardly from the top of said rib, and being bent downwardly at the outer edges of said top portions to form spaced apart side portions that are substantially parallel, the strip being bent inwardly at the lower edges of said side portions to form horizontal flanges, and a reenforcing strip joined to the inner edge of each horizontal flange and extending diagonally up and Outward, and joined to the downwardly extending side portion of the main strip.

8. In a belt conveyor adapted for transporting loose aggregates, a self supporting, belt supporting inverted trough-shaped frame member comprising a pair of main sheet metal strips each bent adjacent one side edge about 105 degrees to degrees forming top depending flanges, said flanges being united into a central rib connecting said portions, the strips having top portions extending outwardly and downwardly from the top of said rib, and being bent downwardly at the outer edges of said top portions to form spaced apart side portions that are substantially parallel, transverse, diagonally extending truss plate means aflixed to said side portions and connecting them, the strip being bent inwardly at the lower edges of said side portions to form horizontal flanges, and a reenforcing strip joined to the inner edge of each horizontal flange and extending diagonally up and outward, and joined to the downwardly extending side portions of the main strip.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 387,727 Middleton Aug. 14, 1888 1,352,263 Harding Sept. 7, 1920 1,691,681 Thomson Nov. 13, 1928 1,928,190 Thomson Sept. 26, 1933 2,386,619 Long et al. Oct. 9, 1945 2,430,282 Ensinger Nov. 4, 1947 2,588,282 Orwin Mar. 4, 1952 FOREIGN PATENTS Number Country Date 423,449 Great Britain Feb. 1, 1935 

